Prof. Alistair McCormick, Plant Engineering Biology, University of Edinburgh (UK)

Many photosynthetic species have evolved CO₂-concentrating mechanisms (CCMs) to improve the efficiency of CO₂ assimilation by Rubisco and reduce the negative impacts of photorespiration. As the majority of plants (i.e. C3 plants) lack an active CCM, introducing a functional heterologous CCM into crops is a key engineering ambition to enhance yield potential. Most algae, including the green alga Chlamydomonas reinhardtii, possess a pyrenoid-based CCM that and enhances CO₂ concentrations in the chloroplast and aggregates Rubisco into a liquid-like phase separated condensate resulting in faster catalysis and decreased photorespiration. Through advances in our understanding of the Chlamydomonas CCM (and more recently those in other species), the complex task of building a functional pyrenoid-based CCM in crops has moved several steps closer to reality, particularly now with a model-based roadmap to guide future engineering efforts. I will outline how pyrenoid-based CCMs can boost plant performance and resilience to climate change and our recent progress in transferring key components and features into plant chloroplasts.